1 | // SPDX-License-Identifier: GPL-2.0-or-later OR copyleft-next-0.3.1 |
2 | /* |
3 | * kmod stress test driver |
4 | * |
5 | * Copyright (C) 2017 Luis R. Rodriguez <mcgrof@kernel.org> |
6 | */ |
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
8 | |
9 | /* |
10 | * This driver provides an interface to trigger and test the kernel's |
11 | * module loader through a series of configurations and a few triggers. |
12 | * To test this driver use the following script as root: |
13 | * |
14 | * tools/testing/selftests/kmod/kmod.sh --help |
15 | */ |
16 | |
17 | #include <linux/kernel.h> |
18 | #include <linux/module.h> |
19 | #include <linux/kmod.h> |
20 | #include <linux/printk.h> |
21 | #include <linux/kthread.h> |
22 | #include <linux/sched.h> |
23 | #include <linux/fs.h> |
24 | #include <linux/miscdevice.h> |
25 | #include <linux/vmalloc.h> |
26 | #include <linux/slab.h> |
27 | #include <linux/device.h> |
28 | |
29 | #define TEST_START_NUM_THREADS 50 |
30 | #define TEST_START_DRIVER "test_module" |
31 | #define TEST_START_TEST_FS "xfs" |
32 | #define TEST_START_TEST_CASE TEST_KMOD_DRIVER |
33 | |
34 | |
35 | static bool force_init_test = false; |
36 | module_param(force_init_test, bool_enable_only, 0644); |
37 | MODULE_PARM_DESC(force_init_test, |
38 | "Force kicking a test immediately after driver loads" ); |
39 | |
40 | /* |
41 | * For device allocation / registration |
42 | */ |
43 | static DEFINE_MUTEX(reg_dev_mutex); |
44 | static LIST_HEAD(reg_test_devs); |
45 | |
46 | /* |
47 | * num_test_devs actually represents the *next* ID of the next |
48 | * device we will allow to create. |
49 | */ |
50 | static int num_test_devs; |
51 | |
52 | /** |
53 | * enum kmod_test_case - linker table test case |
54 | * @TEST_KMOD_DRIVER: stress tests request_module() |
55 | * @TEST_KMOD_FS_TYPE: stress tests get_fs_type() |
56 | * |
57 | * If you add a test case, please be sure to review if you need to set |
58 | * @need_mod_put for your tests case. |
59 | */ |
60 | enum kmod_test_case { |
61 | __TEST_KMOD_INVALID = 0, |
62 | |
63 | TEST_KMOD_DRIVER, |
64 | TEST_KMOD_FS_TYPE, |
65 | |
66 | __TEST_KMOD_MAX, |
67 | }; |
68 | |
69 | struct test_config { |
70 | char *test_driver; |
71 | char *test_fs; |
72 | unsigned int num_threads; |
73 | enum kmod_test_case test_case; |
74 | int test_result; |
75 | }; |
76 | |
77 | struct kmod_test_device; |
78 | |
79 | /** |
80 | * struct kmod_test_device_info - thread info |
81 | * |
82 | * @ret_sync: return value if request_module() is used, sync request for |
83 | * @TEST_KMOD_DRIVER |
84 | * @fs_sync: return value of get_fs_type() for @TEST_KMOD_FS_TYPE |
85 | * @thread_idx: thread ID |
86 | * @test_dev: test device test is being performed under |
87 | * @need_mod_put: Some tests (get_fs_type() is one) requires putting the module |
88 | * (module_put(fs_sync->owner)) when done, otherwise you will not be able |
89 | * to unload the respective modules and re-test. We use this to keep |
90 | * accounting of when we need this and to help out in case we need to |
91 | * error out and deal with module_put() on error. |
92 | */ |
93 | struct kmod_test_device_info { |
94 | int ret_sync; |
95 | struct file_system_type *fs_sync; |
96 | struct task_struct *task_sync; |
97 | unsigned int thread_idx; |
98 | struct kmod_test_device *test_dev; |
99 | bool need_mod_put; |
100 | }; |
101 | |
102 | /** |
103 | * struct kmod_test_device - test device to help test kmod |
104 | * |
105 | * @dev_idx: unique ID for test device |
106 | * @config: configuration for the test |
107 | * @misc_dev: we use a misc device under the hood |
108 | * @dev: pointer to misc_dev's own struct device |
109 | * @config_mutex: protects configuration of test |
110 | * @trigger_mutex: the test trigger can only be fired once at a time |
111 | * @thread_lock: protects @done count, and the @info per each thread |
112 | * @done: number of threads which have completed or failed |
113 | * @test_is_oom: when we run out of memory, use this to halt moving forward |
114 | * @kthreads_done: completion used to signal when all work is done |
115 | * @list: needed to be part of the reg_test_devs |
116 | * @info: array of info for each thread |
117 | */ |
118 | struct kmod_test_device { |
119 | int dev_idx; |
120 | struct test_config config; |
121 | struct miscdevice misc_dev; |
122 | struct device *dev; |
123 | struct mutex config_mutex; |
124 | struct mutex trigger_mutex; |
125 | struct mutex thread_mutex; |
126 | |
127 | unsigned int done; |
128 | |
129 | bool test_is_oom; |
130 | struct completion kthreads_done; |
131 | struct list_head list; |
132 | |
133 | struct kmod_test_device_info *info; |
134 | }; |
135 | |
136 | static const char *test_case_str(enum kmod_test_case test_case) |
137 | { |
138 | switch (test_case) { |
139 | case TEST_KMOD_DRIVER: |
140 | return "TEST_KMOD_DRIVER" ; |
141 | case TEST_KMOD_FS_TYPE: |
142 | return "TEST_KMOD_FS_TYPE" ; |
143 | default: |
144 | return "invalid" ; |
145 | } |
146 | } |
147 | |
148 | static struct miscdevice *dev_to_misc_dev(struct device *dev) |
149 | { |
150 | return dev_get_drvdata(dev); |
151 | } |
152 | |
153 | static struct kmod_test_device *misc_dev_to_test_dev(struct miscdevice *misc_dev) |
154 | { |
155 | return container_of(misc_dev, struct kmod_test_device, misc_dev); |
156 | } |
157 | |
158 | static struct kmod_test_device *dev_to_test_dev(struct device *dev) |
159 | { |
160 | struct miscdevice *misc_dev; |
161 | |
162 | misc_dev = dev_to_misc_dev(dev); |
163 | |
164 | return misc_dev_to_test_dev(misc_dev); |
165 | } |
166 | |
167 | /* Must run with thread_mutex held */ |
168 | static void kmod_test_done_check(struct kmod_test_device *test_dev, |
169 | unsigned int idx) |
170 | { |
171 | struct test_config *config = &test_dev->config; |
172 | |
173 | test_dev->done++; |
174 | dev_dbg(test_dev->dev, "Done thread count: %u\n" , test_dev->done); |
175 | |
176 | if (test_dev->done == config->num_threads) { |
177 | dev_info(test_dev->dev, "Done: %u threads have all run now\n" , |
178 | test_dev->done); |
179 | dev_info(test_dev->dev, "Last thread to run: %u\n" , idx); |
180 | complete(&test_dev->kthreads_done); |
181 | } |
182 | } |
183 | |
184 | static void test_kmod_put_module(struct kmod_test_device_info *info) |
185 | { |
186 | struct kmod_test_device *test_dev = info->test_dev; |
187 | struct test_config *config = &test_dev->config; |
188 | |
189 | if (!info->need_mod_put) |
190 | return; |
191 | |
192 | switch (config->test_case) { |
193 | case TEST_KMOD_DRIVER: |
194 | break; |
195 | case TEST_KMOD_FS_TYPE: |
196 | if (info->fs_sync && info->fs_sync->owner) |
197 | module_put(module: info->fs_sync->owner); |
198 | break; |
199 | default: |
200 | BUG(); |
201 | } |
202 | |
203 | info->need_mod_put = true; |
204 | } |
205 | |
206 | static int run_request(void *data) |
207 | { |
208 | struct kmod_test_device_info *info = data; |
209 | struct kmod_test_device *test_dev = info->test_dev; |
210 | struct test_config *config = &test_dev->config; |
211 | |
212 | switch (config->test_case) { |
213 | case TEST_KMOD_DRIVER: |
214 | info->ret_sync = request_module("%s" , config->test_driver); |
215 | break; |
216 | case TEST_KMOD_FS_TYPE: |
217 | info->fs_sync = get_fs_type(name: config->test_fs); |
218 | info->need_mod_put = true; |
219 | break; |
220 | default: |
221 | /* __trigger_config_run() already checked for test sanity */ |
222 | BUG(); |
223 | return -EINVAL; |
224 | } |
225 | |
226 | dev_dbg(test_dev->dev, "Ran thread %u\n" , info->thread_idx); |
227 | |
228 | test_kmod_put_module(info); |
229 | |
230 | mutex_lock(&test_dev->thread_mutex); |
231 | info->task_sync = NULL; |
232 | kmod_test_done_check(test_dev, idx: info->thread_idx); |
233 | mutex_unlock(lock: &test_dev->thread_mutex); |
234 | |
235 | return 0; |
236 | } |
237 | |
238 | static int tally_work_test(struct kmod_test_device_info *info) |
239 | { |
240 | struct kmod_test_device *test_dev = info->test_dev; |
241 | struct test_config *config = &test_dev->config; |
242 | int err_ret = 0; |
243 | |
244 | switch (config->test_case) { |
245 | case TEST_KMOD_DRIVER: |
246 | /* |
247 | * Only capture errors, if one is found that's |
248 | * enough, for now. |
249 | */ |
250 | if (info->ret_sync != 0) |
251 | err_ret = info->ret_sync; |
252 | dev_info(test_dev->dev, |
253 | "Sync thread %d return status: %d\n" , |
254 | info->thread_idx, info->ret_sync); |
255 | break; |
256 | case TEST_KMOD_FS_TYPE: |
257 | /* For now we make this simple */ |
258 | if (!info->fs_sync) |
259 | err_ret = -EINVAL; |
260 | dev_info(test_dev->dev, "Sync thread %u fs: %s\n" , |
261 | info->thread_idx, info->fs_sync ? config->test_fs : |
262 | "NULL" ); |
263 | break; |
264 | default: |
265 | BUG(); |
266 | } |
267 | |
268 | return err_ret; |
269 | } |
270 | |
271 | /* |
272 | * XXX: add result option to display if all errors did not match. |
273 | * For now we just keep any error code if one was found. |
274 | * |
275 | * If this ran it means *all* tasks were created fine and we |
276 | * are now just collecting results. |
277 | * |
278 | * Only propagate errors, do not override with a subsequent success case. |
279 | */ |
280 | static void tally_up_work(struct kmod_test_device *test_dev) |
281 | { |
282 | struct test_config *config = &test_dev->config; |
283 | struct kmod_test_device_info *info; |
284 | unsigned int idx; |
285 | int err_ret = 0; |
286 | int ret = 0; |
287 | |
288 | mutex_lock(&test_dev->thread_mutex); |
289 | |
290 | dev_info(test_dev->dev, "Results:\n" ); |
291 | |
292 | for (idx=0; idx < config->num_threads; idx++) { |
293 | info = &test_dev->info[idx]; |
294 | ret = tally_work_test(info); |
295 | if (ret) |
296 | err_ret = ret; |
297 | } |
298 | |
299 | /* |
300 | * Note: request_module() returns 256 for a module not found even |
301 | * though modprobe itself returns 1. |
302 | */ |
303 | config->test_result = err_ret; |
304 | |
305 | mutex_unlock(lock: &test_dev->thread_mutex); |
306 | } |
307 | |
308 | static int try_one_request(struct kmod_test_device *test_dev, unsigned int idx) |
309 | { |
310 | struct kmod_test_device_info *info = &test_dev->info[idx]; |
311 | int fail_ret = -ENOMEM; |
312 | |
313 | mutex_lock(&test_dev->thread_mutex); |
314 | |
315 | info->thread_idx = idx; |
316 | info->test_dev = test_dev; |
317 | info->task_sync = kthread_run(run_request, info, "%s-%u" , |
318 | KBUILD_MODNAME, idx); |
319 | |
320 | if (!info->task_sync || IS_ERR(ptr: info->task_sync)) { |
321 | test_dev->test_is_oom = true; |
322 | dev_err(test_dev->dev, "Setting up thread %u failed\n" , idx); |
323 | info->task_sync = NULL; |
324 | goto err_out; |
325 | } else |
326 | dev_dbg(test_dev->dev, "Kicked off thread %u\n" , idx); |
327 | |
328 | mutex_unlock(lock: &test_dev->thread_mutex); |
329 | |
330 | return 0; |
331 | |
332 | err_out: |
333 | info->ret_sync = fail_ret; |
334 | mutex_unlock(lock: &test_dev->thread_mutex); |
335 | |
336 | return fail_ret; |
337 | } |
338 | |
339 | static void test_dev_kmod_stop_tests(struct kmod_test_device *test_dev) |
340 | { |
341 | struct test_config *config = &test_dev->config; |
342 | struct kmod_test_device_info *info; |
343 | unsigned int i; |
344 | |
345 | dev_info(test_dev->dev, "Ending request_module() tests\n" ); |
346 | |
347 | mutex_lock(&test_dev->thread_mutex); |
348 | |
349 | for (i=0; i < config->num_threads; i++) { |
350 | info = &test_dev->info[i]; |
351 | if (info->task_sync && !IS_ERR(ptr: info->task_sync)) { |
352 | dev_info(test_dev->dev, |
353 | "Stopping still-running thread %i\n" , i); |
354 | kthread_stop(k: info->task_sync); |
355 | } |
356 | |
357 | /* |
358 | * info->task_sync is well protected, it can only be |
359 | * NULL or a pointer to a struct. If its NULL we either |
360 | * never ran, or we did and we completed the work. Completed |
361 | * tasks *always* put the module for us. This is a sanity |
362 | * check -- just in case. |
363 | */ |
364 | if (info->task_sync && info->need_mod_put) |
365 | test_kmod_put_module(info); |
366 | } |
367 | |
368 | mutex_unlock(lock: &test_dev->thread_mutex); |
369 | } |
370 | |
371 | /* |
372 | * Only wait *iff* we did not run into any errors during all of our thread |
373 | * set up. If run into any issues we stop threads and just bail out with |
374 | * an error to the trigger. This also means we don't need any tally work |
375 | * for any threads which fail. |
376 | */ |
377 | static int try_requests(struct kmod_test_device *test_dev) |
378 | { |
379 | struct test_config *config = &test_dev->config; |
380 | unsigned int idx; |
381 | int ret; |
382 | bool any_error = false; |
383 | |
384 | for (idx=0; idx < config->num_threads; idx++) { |
385 | if (test_dev->test_is_oom) { |
386 | any_error = true; |
387 | break; |
388 | } |
389 | |
390 | ret = try_one_request(test_dev, idx); |
391 | if (ret) { |
392 | any_error = true; |
393 | break; |
394 | } |
395 | } |
396 | |
397 | if (!any_error) { |
398 | test_dev->test_is_oom = false; |
399 | dev_info(test_dev->dev, |
400 | "No errors were found while initializing threads\n" ); |
401 | wait_for_completion(&test_dev->kthreads_done); |
402 | tally_up_work(test_dev); |
403 | } else { |
404 | test_dev->test_is_oom = true; |
405 | dev_info(test_dev->dev, |
406 | "At least one thread failed to start, stop all work\n" ); |
407 | test_dev_kmod_stop_tests(test_dev); |
408 | return -ENOMEM; |
409 | } |
410 | |
411 | return 0; |
412 | } |
413 | |
414 | static int run_test_driver(struct kmod_test_device *test_dev) |
415 | { |
416 | struct test_config *config = &test_dev->config; |
417 | |
418 | dev_info(test_dev->dev, "Test case: %s (%u)\n" , |
419 | test_case_str(config->test_case), |
420 | config->test_case); |
421 | dev_info(test_dev->dev, "Test driver to load: %s\n" , |
422 | config->test_driver); |
423 | dev_info(test_dev->dev, "Number of threads to run: %u\n" , |
424 | config->num_threads); |
425 | dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n" , |
426 | config->num_threads - 1); |
427 | |
428 | return try_requests(test_dev); |
429 | } |
430 | |
431 | static int run_test_fs_type(struct kmod_test_device *test_dev) |
432 | { |
433 | struct test_config *config = &test_dev->config; |
434 | |
435 | dev_info(test_dev->dev, "Test case: %s (%u)\n" , |
436 | test_case_str(config->test_case), |
437 | config->test_case); |
438 | dev_info(test_dev->dev, "Test filesystem to load: %s\n" , |
439 | config->test_fs); |
440 | dev_info(test_dev->dev, "Number of threads to run: %u\n" , |
441 | config->num_threads); |
442 | dev_info(test_dev->dev, "Thread IDs will range from 0 - %u\n" , |
443 | config->num_threads - 1); |
444 | |
445 | return try_requests(test_dev); |
446 | } |
447 | |
448 | static ssize_t config_show(struct device *dev, |
449 | struct device_attribute *attr, |
450 | char *buf) |
451 | { |
452 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
453 | struct test_config *config = &test_dev->config; |
454 | int len = 0; |
455 | |
456 | mutex_lock(&test_dev->config_mutex); |
457 | |
458 | len += snprintf(buf, PAGE_SIZE, |
459 | fmt: "Custom trigger configuration for: %s\n" , |
460 | dev_name(dev)); |
461 | |
462 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
463 | fmt: "Number of threads:\t%u\n" , |
464 | config->num_threads); |
465 | |
466 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
467 | fmt: "Test_case:\t%s (%u)\n" , |
468 | test_case_str(test_case: config->test_case), |
469 | config->test_case); |
470 | |
471 | if (config->test_driver) |
472 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
473 | fmt: "driver:\t%s\n" , |
474 | config->test_driver); |
475 | else |
476 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
477 | fmt: "driver:\tEMPTY\n" ); |
478 | |
479 | if (config->test_fs) |
480 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
481 | fmt: "fs:\t%s\n" , |
482 | config->test_fs); |
483 | else |
484 | len += snprintf(buf: buf+len, PAGE_SIZE - len, |
485 | fmt: "fs:\tEMPTY\n" ); |
486 | |
487 | mutex_unlock(lock: &test_dev->config_mutex); |
488 | |
489 | return len; |
490 | } |
491 | static DEVICE_ATTR_RO(config); |
492 | |
493 | /* |
494 | * This ensures we don't allow kicking threads through if our configuration |
495 | * is faulty. |
496 | */ |
497 | static int __trigger_config_run(struct kmod_test_device *test_dev) |
498 | { |
499 | struct test_config *config = &test_dev->config; |
500 | |
501 | test_dev->done = 0; |
502 | |
503 | switch (config->test_case) { |
504 | case TEST_KMOD_DRIVER: |
505 | return run_test_driver(test_dev); |
506 | case TEST_KMOD_FS_TYPE: |
507 | return run_test_fs_type(test_dev); |
508 | default: |
509 | dev_warn(test_dev->dev, |
510 | "Invalid test case requested: %u\n" , |
511 | config->test_case); |
512 | return -EINVAL; |
513 | } |
514 | } |
515 | |
516 | static int trigger_config_run(struct kmod_test_device *test_dev) |
517 | { |
518 | struct test_config *config = &test_dev->config; |
519 | int ret; |
520 | |
521 | mutex_lock(&test_dev->trigger_mutex); |
522 | mutex_lock(&test_dev->config_mutex); |
523 | |
524 | ret = __trigger_config_run(test_dev); |
525 | if (ret < 0) |
526 | goto out; |
527 | dev_info(test_dev->dev, "General test result: %d\n" , |
528 | config->test_result); |
529 | |
530 | /* |
531 | * We must return 0 after a trigger even unless something went |
532 | * wrong with the setup of the test. If the test setup went fine |
533 | * then userspace must just check the result of config->test_result. |
534 | * One issue with relying on the return from a call in the kernel |
535 | * is if the kernel returns a positive value using this trigger |
536 | * will not return the value to userspace, it would be lost. |
537 | * |
538 | * By not relying on capturing the return value of tests we are using |
539 | * through the trigger it also us to run tests with set -e and only |
540 | * fail when something went wrong with the driver upon trigger |
541 | * requests. |
542 | */ |
543 | ret = 0; |
544 | |
545 | out: |
546 | mutex_unlock(lock: &test_dev->config_mutex); |
547 | mutex_unlock(lock: &test_dev->trigger_mutex); |
548 | |
549 | return ret; |
550 | } |
551 | |
552 | static ssize_t |
553 | trigger_config_store(struct device *dev, |
554 | struct device_attribute *attr, |
555 | const char *buf, size_t count) |
556 | { |
557 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
558 | int ret; |
559 | |
560 | if (test_dev->test_is_oom) |
561 | return -ENOMEM; |
562 | |
563 | /* For all intents and purposes we don't care what userspace |
564 | * sent this trigger, we care only that we were triggered. |
565 | * We treat the return value only for caputuring issues with |
566 | * the test setup. At this point all the test variables should |
567 | * have been allocated so typically this should never fail. |
568 | */ |
569 | ret = trigger_config_run(test_dev); |
570 | if (unlikely(ret < 0)) |
571 | goto out; |
572 | |
573 | /* |
574 | * Note: any return > 0 will be treated as success |
575 | * and the error value will not be available to userspace. |
576 | * Do not rely on trying to send to userspace a test value |
577 | * return value as positive return errors will be lost. |
578 | */ |
579 | if (WARN_ON(ret > 0)) |
580 | return -EINVAL; |
581 | |
582 | ret = count; |
583 | out: |
584 | return ret; |
585 | } |
586 | static DEVICE_ATTR_WO(trigger_config); |
587 | |
588 | /* |
589 | * XXX: move to kstrncpy() once merged. |
590 | * |
591 | * Users should use kfree_const() when freeing these. |
592 | */ |
593 | static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp) |
594 | { |
595 | *dst = kstrndup(s: name, len: count, gfp); |
596 | if (!*dst) |
597 | return -ENOSPC; |
598 | return count; |
599 | } |
600 | |
601 | static int config_copy_test_driver_name(struct test_config *config, |
602 | const char *name, |
603 | size_t count) |
604 | { |
605 | return __kstrncpy(dst: &config->test_driver, name, count, GFP_KERNEL); |
606 | } |
607 | |
608 | |
609 | static int config_copy_test_fs(struct test_config *config, const char *name, |
610 | size_t count) |
611 | { |
612 | return __kstrncpy(dst: &config->test_fs, name, count, GFP_KERNEL); |
613 | } |
614 | |
615 | static void __kmod_config_free(struct test_config *config) |
616 | { |
617 | if (!config) |
618 | return; |
619 | |
620 | kfree_const(x: config->test_driver); |
621 | config->test_driver = NULL; |
622 | |
623 | kfree_const(x: config->test_fs); |
624 | config->test_fs = NULL; |
625 | } |
626 | |
627 | static void kmod_config_free(struct kmod_test_device *test_dev) |
628 | { |
629 | struct test_config *config; |
630 | |
631 | if (!test_dev) |
632 | return; |
633 | |
634 | config = &test_dev->config; |
635 | |
636 | mutex_lock(&test_dev->config_mutex); |
637 | __kmod_config_free(config); |
638 | mutex_unlock(lock: &test_dev->config_mutex); |
639 | } |
640 | |
641 | static ssize_t config_test_driver_store(struct device *dev, |
642 | struct device_attribute *attr, |
643 | const char *buf, size_t count) |
644 | { |
645 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
646 | struct test_config *config = &test_dev->config; |
647 | int copied; |
648 | |
649 | mutex_lock(&test_dev->config_mutex); |
650 | |
651 | kfree_const(x: config->test_driver); |
652 | config->test_driver = NULL; |
653 | |
654 | copied = config_copy_test_driver_name(config, name: buf, count); |
655 | mutex_unlock(lock: &test_dev->config_mutex); |
656 | |
657 | return copied; |
658 | } |
659 | |
660 | /* |
661 | * As per sysfs_kf_seq_show() the buf is max PAGE_SIZE. |
662 | */ |
663 | static ssize_t config_test_show_str(struct mutex *config_mutex, |
664 | char *dst, |
665 | char *src) |
666 | { |
667 | int len; |
668 | |
669 | mutex_lock(config_mutex); |
670 | len = snprintf(buf: dst, PAGE_SIZE, fmt: "%s\n" , src); |
671 | mutex_unlock(lock: config_mutex); |
672 | |
673 | return len; |
674 | } |
675 | |
676 | static ssize_t config_test_driver_show(struct device *dev, |
677 | struct device_attribute *attr, |
678 | char *buf) |
679 | { |
680 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
681 | struct test_config *config = &test_dev->config; |
682 | |
683 | return config_test_show_str(config_mutex: &test_dev->config_mutex, dst: buf, |
684 | src: config->test_driver); |
685 | } |
686 | static DEVICE_ATTR_RW(config_test_driver); |
687 | |
688 | static ssize_t config_test_fs_store(struct device *dev, |
689 | struct device_attribute *attr, |
690 | const char *buf, size_t count) |
691 | { |
692 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
693 | struct test_config *config = &test_dev->config; |
694 | int copied; |
695 | |
696 | mutex_lock(&test_dev->config_mutex); |
697 | |
698 | kfree_const(x: config->test_fs); |
699 | config->test_fs = NULL; |
700 | |
701 | copied = config_copy_test_fs(config, name: buf, count); |
702 | mutex_unlock(lock: &test_dev->config_mutex); |
703 | |
704 | return copied; |
705 | } |
706 | |
707 | static ssize_t config_test_fs_show(struct device *dev, |
708 | struct device_attribute *attr, |
709 | char *buf) |
710 | { |
711 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
712 | struct test_config *config = &test_dev->config; |
713 | |
714 | return config_test_show_str(config_mutex: &test_dev->config_mutex, dst: buf, |
715 | src: config->test_fs); |
716 | } |
717 | static DEVICE_ATTR_RW(config_test_fs); |
718 | |
719 | static int trigger_config_run_type(struct kmod_test_device *test_dev, |
720 | enum kmod_test_case test_case, |
721 | const char *test_str) |
722 | { |
723 | int copied = 0; |
724 | struct test_config *config = &test_dev->config; |
725 | |
726 | mutex_lock(&test_dev->config_mutex); |
727 | |
728 | switch (test_case) { |
729 | case TEST_KMOD_DRIVER: |
730 | kfree_const(x: config->test_driver); |
731 | config->test_driver = NULL; |
732 | copied = config_copy_test_driver_name(config, name: test_str, |
733 | strlen(test_str)); |
734 | break; |
735 | case TEST_KMOD_FS_TYPE: |
736 | kfree_const(x: config->test_fs); |
737 | config->test_fs = NULL; |
738 | copied = config_copy_test_fs(config, name: test_str, |
739 | strlen(test_str)); |
740 | break; |
741 | default: |
742 | mutex_unlock(lock: &test_dev->config_mutex); |
743 | return -EINVAL; |
744 | } |
745 | |
746 | config->test_case = test_case; |
747 | |
748 | mutex_unlock(lock: &test_dev->config_mutex); |
749 | |
750 | if (copied <= 0 || copied != strlen(test_str)) { |
751 | test_dev->test_is_oom = true; |
752 | return -ENOMEM; |
753 | } |
754 | |
755 | test_dev->test_is_oom = false; |
756 | |
757 | return trigger_config_run(test_dev); |
758 | } |
759 | |
760 | static void free_test_dev_info(struct kmod_test_device *test_dev) |
761 | { |
762 | vfree(addr: test_dev->info); |
763 | test_dev->info = NULL; |
764 | } |
765 | |
766 | static int kmod_config_sync_info(struct kmod_test_device *test_dev) |
767 | { |
768 | struct test_config *config = &test_dev->config; |
769 | |
770 | free_test_dev_info(test_dev); |
771 | test_dev->info = |
772 | vzalloc(array_size(sizeof(struct kmod_test_device_info), |
773 | config->num_threads)); |
774 | if (!test_dev->info) |
775 | return -ENOMEM; |
776 | |
777 | return 0; |
778 | } |
779 | |
780 | /* |
781 | * Old kernels may not have this, if you want to port this code to |
782 | * test it on older kernels. |
783 | */ |
784 | #ifdef get_kmod_umh_limit |
785 | static unsigned int kmod_init_test_thread_limit(void) |
786 | { |
787 | return get_kmod_umh_limit(); |
788 | } |
789 | #else |
790 | static unsigned int kmod_init_test_thread_limit(void) |
791 | { |
792 | return TEST_START_NUM_THREADS; |
793 | } |
794 | #endif |
795 | |
796 | static int __kmod_config_init(struct kmod_test_device *test_dev) |
797 | { |
798 | struct test_config *config = &test_dev->config; |
799 | int ret = -ENOMEM, copied; |
800 | |
801 | __kmod_config_free(config); |
802 | |
803 | copied = config_copy_test_driver_name(config, TEST_START_DRIVER, |
804 | strlen(TEST_START_DRIVER)); |
805 | if (copied != strlen(TEST_START_DRIVER)) |
806 | goto err_out; |
807 | |
808 | copied = config_copy_test_fs(config, TEST_START_TEST_FS, |
809 | strlen(TEST_START_TEST_FS)); |
810 | if (copied != strlen(TEST_START_TEST_FS)) |
811 | goto err_out; |
812 | |
813 | config->num_threads = kmod_init_test_thread_limit(); |
814 | config->test_result = 0; |
815 | config->test_case = TEST_START_TEST_CASE; |
816 | |
817 | ret = kmod_config_sync_info(test_dev); |
818 | if (ret) |
819 | goto err_out; |
820 | |
821 | test_dev->test_is_oom = false; |
822 | |
823 | return 0; |
824 | |
825 | err_out: |
826 | test_dev->test_is_oom = true; |
827 | WARN_ON(test_dev->test_is_oom); |
828 | |
829 | __kmod_config_free(config); |
830 | |
831 | return ret; |
832 | } |
833 | |
834 | static ssize_t reset_store(struct device *dev, |
835 | struct device_attribute *attr, |
836 | const char *buf, size_t count) |
837 | { |
838 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
839 | int ret; |
840 | |
841 | mutex_lock(&test_dev->trigger_mutex); |
842 | mutex_lock(&test_dev->config_mutex); |
843 | |
844 | ret = __kmod_config_init(test_dev); |
845 | if (ret < 0) { |
846 | ret = -ENOMEM; |
847 | dev_err(dev, "could not alloc settings for config trigger: %d\n" , |
848 | ret); |
849 | goto out; |
850 | } |
851 | |
852 | dev_info(dev, "reset\n" ); |
853 | ret = count; |
854 | |
855 | out: |
856 | mutex_unlock(lock: &test_dev->config_mutex); |
857 | mutex_unlock(lock: &test_dev->trigger_mutex); |
858 | |
859 | return ret; |
860 | } |
861 | static DEVICE_ATTR_WO(reset); |
862 | |
863 | static int test_dev_config_update_uint_sync(struct kmod_test_device *test_dev, |
864 | const char *buf, size_t size, |
865 | unsigned int *config, |
866 | int (*test_sync)(struct kmod_test_device *test_dev)) |
867 | { |
868 | int ret; |
869 | unsigned int val; |
870 | unsigned int old_val; |
871 | |
872 | ret = kstrtouint(s: buf, base: 10, res: &val); |
873 | if (ret) |
874 | return ret; |
875 | |
876 | mutex_lock(&test_dev->config_mutex); |
877 | |
878 | old_val = *config; |
879 | *(unsigned int *)config = val; |
880 | |
881 | ret = test_sync(test_dev); |
882 | if (ret) { |
883 | *(unsigned int *)config = old_val; |
884 | |
885 | ret = test_sync(test_dev); |
886 | WARN_ON(ret); |
887 | |
888 | mutex_unlock(lock: &test_dev->config_mutex); |
889 | return -EINVAL; |
890 | } |
891 | |
892 | mutex_unlock(lock: &test_dev->config_mutex); |
893 | /* Always return full write size even if we didn't consume all */ |
894 | return size; |
895 | } |
896 | |
897 | static int test_dev_config_update_uint_range(struct kmod_test_device *test_dev, |
898 | const char *buf, size_t size, |
899 | unsigned int *config, |
900 | unsigned int min, |
901 | unsigned int max) |
902 | { |
903 | unsigned int val; |
904 | int ret; |
905 | |
906 | ret = kstrtouint(s: buf, base: 10, res: &val); |
907 | if (ret) |
908 | return ret; |
909 | |
910 | if (val < min || val > max) |
911 | return -EINVAL; |
912 | |
913 | mutex_lock(&test_dev->config_mutex); |
914 | *config = val; |
915 | mutex_unlock(lock: &test_dev->config_mutex); |
916 | |
917 | /* Always return full write size even if we didn't consume all */ |
918 | return size; |
919 | } |
920 | |
921 | static int test_dev_config_update_int(struct kmod_test_device *test_dev, |
922 | const char *buf, size_t size, |
923 | int *config) |
924 | { |
925 | int val; |
926 | int ret; |
927 | |
928 | ret = kstrtoint(s: buf, base: 10, res: &val); |
929 | if (ret) |
930 | return ret; |
931 | |
932 | mutex_lock(&test_dev->config_mutex); |
933 | *config = val; |
934 | mutex_unlock(lock: &test_dev->config_mutex); |
935 | /* Always return full write size even if we didn't consume all */ |
936 | return size; |
937 | } |
938 | |
939 | static ssize_t test_dev_config_show_int(struct kmod_test_device *test_dev, |
940 | char *buf, |
941 | int config) |
942 | { |
943 | int val; |
944 | |
945 | mutex_lock(&test_dev->config_mutex); |
946 | val = config; |
947 | mutex_unlock(lock: &test_dev->config_mutex); |
948 | |
949 | return snprintf(buf, PAGE_SIZE, fmt: "%d\n" , val); |
950 | } |
951 | |
952 | static ssize_t test_dev_config_show_uint(struct kmod_test_device *test_dev, |
953 | char *buf, |
954 | unsigned int config) |
955 | { |
956 | unsigned int val; |
957 | |
958 | mutex_lock(&test_dev->config_mutex); |
959 | val = config; |
960 | mutex_unlock(lock: &test_dev->config_mutex); |
961 | |
962 | return snprintf(buf, PAGE_SIZE, fmt: "%u\n" , val); |
963 | } |
964 | |
965 | static ssize_t test_result_store(struct device *dev, |
966 | struct device_attribute *attr, |
967 | const char *buf, size_t count) |
968 | { |
969 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
970 | struct test_config *config = &test_dev->config; |
971 | |
972 | return test_dev_config_update_int(test_dev, buf, size: count, |
973 | config: &config->test_result); |
974 | } |
975 | |
976 | static ssize_t config_num_threads_store(struct device *dev, |
977 | struct device_attribute *attr, |
978 | const char *buf, size_t count) |
979 | { |
980 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
981 | struct test_config *config = &test_dev->config; |
982 | |
983 | return test_dev_config_update_uint_sync(test_dev, buf, size: count, |
984 | config: &config->num_threads, |
985 | test_sync: kmod_config_sync_info); |
986 | } |
987 | |
988 | static ssize_t config_num_threads_show(struct device *dev, |
989 | struct device_attribute *attr, |
990 | char *buf) |
991 | { |
992 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
993 | struct test_config *config = &test_dev->config; |
994 | |
995 | return test_dev_config_show_int(test_dev, buf, config: config->num_threads); |
996 | } |
997 | static DEVICE_ATTR_RW(config_num_threads); |
998 | |
999 | static ssize_t config_test_case_store(struct device *dev, |
1000 | struct device_attribute *attr, |
1001 | const char *buf, size_t count) |
1002 | { |
1003 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
1004 | struct test_config *config = &test_dev->config; |
1005 | |
1006 | return test_dev_config_update_uint_range(test_dev, buf, size: count, |
1007 | config: &config->test_case, |
1008 | min: __TEST_KMOD_INVALID + 1, |
1009 | max: __TEST_KMOD_MAX - 1); |
1010 | } |
1011 | |
1012 | static ssize_t config_test_case_show(struct device *dev, |
1013 | struct device_attribute *attr, |
1014 | char *buf) |
1015 | { |
1016 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
1017 | struct test_config *config = &test_dev->config; |
1018 | |
1019 | return test_dev_config_show_uint(test_dev, buf, config: config->test_case); |
1020 | } |
1021 | static DEVICE_ATTR_RW(config_test_case); |
1022 | |
1023 | static ssize_t test_result_show(struct device *dev, |
1024 | struct device_attribute *attr, |
1025 | char *buf) |
1026 | { |
1027 | struct kmod_test_device *test_dev = dev_to_test_dev(dev); |
1028 | struct test_config *config = &test_dev->config; |
1029 | |
1030 | return test_dev_config_show_int(test_dev, buf, config: config->test_result); |
1031 | } |
1032 | static DEVICE_ATTR_RW(test_result); |
1033 | |
1034 | #define TEST_KMOD_DEV_ATTR(name) &dev_attr_##name.attr |
1035 | |
1036 | static struct attribute *test_dev_attrs[] = { |
1037 | TEST_KMOD_DEV_ATTR(trigger_config), |
1038 | TEST_KMOD_DEV_ATTR(config), |
1039 | TEST_KMOD_DEV_ATTR(reset), |
1040 | |
1041 | TEST_KMOD_DEV_ATTR(config_test_driver), |
1042 | TEST_KMOD_DEV_ATTR(config_test_fs), |
1043 | TEST_KMOD_DEV_ATTR(config_num_threads), |
1044 | TEST_KMOD_DEV_ATTR(config_test_case), |
1045 | TEST_KMOD_DEV_ATTR(test_result), |
1046 | |
1047 | NULL, |
1048 | }; |
1049 | |
1050 | ATTRIBUTE_GROUPS(test_dev); |
1051 | |
1052 | static int kmod_config_init(struct kmod_test_device *test_dev) |
1053 | { |
1054 | int ret; |
1055 | |
1056 | mutex_lock(&test_dev->config_mutex); |
1057 | ret = __kmod_config_init(test_dev); |
1058 | mutex_unlock(lock: &test_dev->config_mutex); |
1059 | |
1060 | return ret; |
1061 | } |
1062 | |
1063 | static struct kmod_test_device *alloc_test_dev_kmod(int idx) |
1064 | { |
1065 | int ret; |
1066 | struct kmod_test_device *test_dev; |
1067 | struct miscdevice *misc_dev; |
1068 | |
1069 | test_dev = vzalloc(size: sizeof(struct kmod_test_device)); |
1070 | if (!test_dev) |
1071 | goto err_out; |
1072 | |
1073 | mutex_init(&test_dev->config_mutex); |
1074 | mutex_init(&test_dev->trigger_mutex); |
1075 | mutex_init(&test_dev->thread_mutex); |
1076 | |
1077 | init_completion(x: &test_dev->kthreads_done); |
1078 | |
1079 | ret = kmod_config_init(test_dev); |
1080 | if (ret < 0) { |
1081 | pr_err("Cannot alloc kmod_config_init()\n" ); |
1082 | goto err_out_free; |
1083 | } |
1084 | |
1085 | test_dev->dev_idx = idx; |
1086 | misc_dev = &test_dev->misc_dev; |
1087 | |
1088 | misc_dev->minor = MISC_DYNAMIC_MINOR; |
1089 | misc_dev->name = kasprintf(GFP_KERNEL, fmt: "test_kmod%d" , idx); |
1090 | if (!misc_dev->name) { |
1091 | pr_err("Cannot alloc misc_dev->name\n" ); |
1092 | goto err_out_free_config; |
1093 | } |
1094 | misc_dev->groups = test_dev_groups; |
1095 | |
1096 | return test_dev; |
1097 | |
1098 | err_out_free_config: |
1099 | free_test_dev_info(test_dev); |
1100 | kmod_config_free(test_dev); |
1101 | err_out_free: |
1102 | vfree(addr: test_dev); |
1103 | test_dev = NULL; |
1104 | err_out: |
1105 | return NULL; |
1106 | } |
1107 | |
1108 | static void free_test_dev_kmod(struct kmod_test_device *test_dev) |
1109 | { |
1110 | if (test_dev) { |
1111 | kfree_const(x: test_dev->misc_dev.name); |
1112 | test_dev->misc_dev.name = NULL; |
1113 | free_test_dev_info(test_dev); |
1114 | kmod_config_free(test_dev); |
1115 | vfree(addr: test_dev); |
1116 | test_dev = NULL; |
1117 | } |
1118 | } |
1119 | |
1120 | static struct kmod_test_device *register_test_dev_kmod(void) |
1121 | { |
1122 | struct kmod_test_device *test_dev = NULL; |
1123 | int ret; |
1124 | |
1125 | mutex_lock(®_dev_mutex); |
1126 | |
1127 | /* int should suffice for number of devices, test for wrap */ |
1128 | if (num_test_devs + 1 == INT_MAX) { |
1129 | pr_err("reached limit of number of test devices\n" ); |
1130 | goto out; |
1131 | } |
1132 | |
1133 | test_dev = alloc_test_dev_kmod(idx: num_test_devs); |
1134 | if (!test_dev) |
1135 | goto out; |
1136 | |
1137 | ret = misc_register(misc: &test_dev->misc_dev); |
1138 | if (ret) { |
1139 | pr_err("could not register misc device: %d\n" , ret); |
1140 | free_test_dev_kmod(test_dev); |
1141 | test_dev = NULL; |
1142 | goto out; |
1143 | } |
1144 | |
1145 | test_dev->dev = test_dev->misc_dev.this_device; |
1146 | list_add_tail(new: &test_dev->list, head: ®_test_devs); |
1147 | dev_info(test_dev->dev, "interface ready\n" ); |
1148 | |
1149 | num_test_devs++; |
1150 | |
1151 | out: |
1152 | mutex_unlock(lock: ®_dev_mutex); |
1153 | |
1154 | return test_dev; |
1155 | |
1156 | } |
1157 | |
1158 | static int __init test_kmod_init(void) |
1159 | { |
1160 | struct kmod_test_device *test_dev; |
1161 | int ret; |
1162 | |
1163 | test_dev = register_test_dev_kmod(); |
1164 | if (!test_dev) { |
1165 | pr_err("Cannot add first test kmod device\n" ); |
1166 | return -ENODEV; |
1167 | } |
1168 | |
1169 | /* |
1170 | * With some work we might be able to gracefully enable |
1171 | * testing with this driver built-in, for now this seems |
1172 | * rather risky. For those willing to try have at it, |
1173 | * and enable the below. Good luck! If that works, try |
1174 | * lowering the init level for more fun. |
1175 | */ |
1176 | if (force_init_test) { |
1177 | ret = trigger_config_run_type(test_dev, |
1178 | test_case: TEST_KMOD_DRIVER, test_str: "tun" ); |
1179 | if (WARN_ON(ret)) |
1180 | return ret; |
1181 | ret = trigger_config_run_type(test_dev, |
1182 | test_case: TEST_KMOD_FS_TYPE, test_str: "btrfs" ); |
1183 | if (WARN_ON(ret)) |
1184 | return ret; |
1185 | } |
1186 | |
1187 | return 0; |
1188 | } |
1189 | late_initcall(test_kmod_init); |
1190 | |
1191 | static |
1192 | void unregister_test_dev_kmod(struct kmod_test_device *test_dev) |
1193 | { |
1194 | mutex_lock(&test_dev->trigger_mutex); |
1195 | mutex_lock(&test_dev->config_mutex); |
1196 | |
1197 | test_dev_kmod_stop_tests(test_dev); |
1198 | |
1199 | dev_info(test_dev->dev, "removing interface\n" ); |
1200 | misc_deregister(misc: &test_dev->misc_dev); |
1201 | |
1202 | mutex_unlock(lock: &test_dev->config_mutex); |
1203 | mutex_unlock(lock: &test_dev->trigger_mutex); |
1204 | |
1205 | free_test_dev_kmod(test_dev); |
1206 | } |
1207 | |
1208 | static void __exit test_kmod_exit(void) |
1209 | { |
1210 | struct kmod_test_device *test_dev, *tmp; |
1211 | |
1212 | mutex_lock(®_dev_mutex); |
1213 | list_for_each_entry_safe(test_dev, tmp, ®_test_devs, list) { |
1214 | list_del(entry: &test_dev->list); |
1215 | unregister_test_dev_kmod(test_dev); |
1216 | } |
1217 | mutex_unlock(lock: ®_dev_mutex); |
1218 | } |
1219 | module_exit(test_kmod_exit); |
1220 | |
1221 | MODULE_AUTHOR("Luis R. Rodriguez <mcgrof@kernel.org>" ); |
1222 | MODULE_LICENSE("GPL" ); |
1223 | |